27 lines
1.3 KiB
Markdown
27 lines
1.3 KiB
Markdown
## STM Original Electronics
|
|
This directory contains the documentation of the original control electronics of the STM. We did some modifications which are detailed below.
|
|
|
|
### Overview
|
|
|
|
|
|
The **Control Box** schematic can be found in [`STM_Main_neu_Schaltplan_3.pdf`](./STM_Main_neu_Schaltplan_3.pdf).
|
|
|
|
The **Preamplifier** schematic is [`STM_Vorverst_neu_2.pdf`](./STM_Vorverst_neu_2.pdf).
|
|
|
|
### Modifications
|
|
|
|
- Preamplifier
|
|
- *[2025-06-14]* Added a 1nF capacitor parallel to `R10` to mitigate 12kHz
|
|
oscillation and stabilize the amplifier.
|
|
- Control Box
|
|
- *[2025-06-14]* Disconnected `R36` from `R1`/`C1` and instead connected it
|
|
to -15V through a separate 10k resistor. This inverts the setpoint
|
|
voltage, which was necessary to make the differentiator actually calculate
|
|
an error difference. Previously, it was summing the setpoint and control
|
|
variable...
|
|
- *[2025-06-14]* Cut out `R8`, the resistor parallel to the capacitor of the
|
|
integrator (I-controller). This resistor was preventing the integrator
|
|
from stably integrating at very low frequencies.
|
|
- *[2025-06-15]* Added a 1µF capacitor parallel to `C7`. This mitigates 1.47
|
|
kHz oscillation when the amplifier gain is high.
|